MX2012013121A - Polyamide resin. - Google Patents

Abstract

Provided is a polyamide resin which exhibits an excellent color tone and has a high elastic modulus, excellent gas barrier properties, and a low water absorption rate. The polyamide resin is a polyamide resin, in which at least 70 mol% of diamine constituent units are derived from xylylenediamine (A-1) and/or bis(aminomethyl)cyclohexane (A-2), and at least 50 mol% of dicarboxylic acid constituent units are derived from sebacic acid (B), and which is characterized by having a sulfur atom concentration of 1 to 200 ppm by mass.

Description

POLYAMIDE RESIN TECHNICAL FIELD The present invention relates to polyamide resin compositions, specifically polyamide resins having an excellent color tone and elastic modulus as well as excellent gas barrier properties and low water absorption.

BACKGROUND OF THE TECHNIQUE Polyamide resins are widely used as engineering plastics having excellent mechanical strength such as impact resistance and resistance to friction / abrasion as well as excellent heat resistance or oil resistance in the fields of automotive parts, electronic equipment parts / electrical, office automation equipment parts, mechanical parts, construction materials / parts of homes and the like, and recently an increasingly wide application has been found.

Many kinds of polyamides include, for example, polyamide 6 and polyamide 66 are known, among which adipamide m-xylyne. { successively, sometimes referred to as "polyamide MXD6") derived from m-xylylenediamine and adipic acid it is positioned as a very excellent polyamide because it contains an aromatic ring in the main chain other than polyamide 6 and polyamide 66 so that it has a high rigidity, low water absorption and excellent oil resistance as well as a low shrinkage ratio during molding and causes a small shrinkage or wrap, which means that it is also suitable for precision molding. Accordingly, the polyamide MXD6 has recently been used with a greater width as a molding material, especially as an extrusion molding material in various fields including vehicle parts such as automobiles, machinery parts in general, parts of precision machinery, parts of electronic / electrical equipment, leisure / sports items, civil engineering and construction materials, etc.

The polyamide MXD6 has a low water absorption when compared to other polyamide resins such as polyamide 66, but there is a need for molding materials that have even less water absorption to meet the recent demand requirements.

Light and strong polyamide resin materials are also needed. A xylylene polyamide resin lighter than polyamide MXD6 and having a lower water absorption includes a xylylene sebacamide resin derived from xylylenediamine and sebacic acid (hereinafter, sometimes referred to as "polyamide XD10").

However, polyamide resins containing xylylenediamine as a structural unit are more prone to yellowing than polyamide 6 and the like because they tend to generate radicals at the benzylmethylene sites for structural reasons. The applicant proposed a method for the prevention of yellowing of the polyamide XD6 by the addition of a phosphorus antioxidant and an alkaline component in the polyamide resin (patent document 1). An anti-yellowing effect can be achieved by this method, but this method was difficult to use for some applications due to the addition of a sufficient phosphorus antioxidant to prevent yellowing from increasing costs or a phosphorus compound can be deposited on a filter or a similar during the extrusion molding of a film.

As an alternative to the polyamide resins containing a xylylenediamine derivative unit as a structural unit, the polyamide resins derived from bis (aminomethyl) cyclohexane do not have a benzylmethylene and dicarboxylic acid site (hereinafter, sometimes referred to as as "BAC 10 polyamides") it is expected that they have a high resistance to aging by heating. However, even BAC polyamides are not free of problems due to yellowing, and a polyamide resin derived from bis (aminomethyl) cyclohexane and sebacic acid (hereinafter, sometimes referred to as "polyamide BAC 10") recently designated as A polyamide BAC having especially a low water absorption also has problems with yellowing and resistance to aging by heating.

REFERENCES DOCUMENTS OF PATENT Patent Document 1: JP-A 2007-31475 DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION It is an object of the present invention to solve the aforementioned problems to provide a resistant polyamide XD10 yellowing or BAM10 polyamide resins.

MEANS TO SOLVE THE PROBLEMS As a result of careful studies to obtain a polyamide resin XD10 or BAC10 resistant to yellowing, we have achieved the present invention based on the surprising discovery that an anti-yellowing effect can be obtained by controlling the amount of sulfur contained in a resin of polyamide XD10 or BAC10 itself to a specific amount without relying on additives.

Accordingly, a first aspect of the present invention provides a polyamide resin comprising a diamine structural unit and a dicarboxylic acid structural unit, wherein 70 mol% or more of the diamine structural unit is derived from xylylenediamine (Al) and / or bis (aminomethyl) cyclohexane (A-2) and 50 mol or more of the structural unit of dicarboxylic acid is derived from sebacic acid (B); and which has a sulfur atom concentration of 1 to 200 ppm per mass.

A second aspect of the present invention provides the polyamide resin according to the first aspect, which has a phosphorus atom concentration of 1 to 500 ppm by mass.

A third aspect of the present invention provides the polyamide resin according to the first or second aspect, which has a sodium atom concentration of 1 to 500 ppm by mass.

A fourth aspect of the present invention provides the polyamide resin according to the first aspect, wherein the xylylenediamine (A-1) is m-xylylenediamine, p-xylylenediamine or a mixture thereof.

A fifth aspect of the present invention provides the polyamide resin according to the first aspect, wherein the bis (aminomethyl) cyclohexane (A-2) is 1, -bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane or a mixture thereof.

A sixth aspect of the present invention provides the polyamide resin according to the first aspect, wherein the structural unit of dicarboxylic acid is derived from sebacic acid (B).

A seventh aspect of the present invention provides the polyamide resin according to the first aspect, which has an average molecular weight number of 10,000 to 50,000.

An eighth aspect of the present invention provides the polyamide resin according to the first aspect, wherein the molar reaction ratio of the diamine component to the dicarboxylic acid component represented by the following equation (1) is 0.98-1.1; r = (l-cN-b < CN)) / (1-cC + a (CN)) (1) where a = Mi / 2, b = M2 / 2, c = 18.015, where Mi represents the molecular weight of the diamine component (g / mol), M2 represents the molecular weight of the dicarboxylic acid component (g / mol), N represents the concentration of a terminal amino group (eq / g), and C represents the concentration of a carboxyl terminal group (eq / g).

A ninth aspect of the present invention provides an article molded by molding a polyamide resin according to any of the first to eighth aspects.

ADVANTAGES OF THE INVENTION The polyamide resins of the present invention possess an excellent color tone and elastic modulus, excellent gas barrier properties, low water absorption and high resistance to aging by heating.

Accordingly, the polyamide resins of the present invention can be suitably used for a wide variety of moldings including various films, sheets, laminated films, laminated sheets, pipes, tubing, miscellaneous containers such as empty containers and bottles, various pieces of equipment. electric / electronic and the like.

THE BEST WAY TO CARRY OUT THE INVENTION Polyamide resins The polyamide resins of the present invention comprise a diamine structural unit and a dicarboxylic acid structural unit, wherein 70 mol% or more of the diamine structural unit is derived from xylylenediamine (Al) and / or bis (aminomethyl) cyclohexane (A-2) and 50 mol% or more of the structural unit of dicarboxylic acid is derived from sebacic acid (B); and which has a sulfur atom concentration of 1 to 200 ppm per mass.

As used hereafter, "ppm" is defined to mean "ppm by mass".

The polyamide resins of the present invention possess an excellent color tone as evidenced by the Upper Yellowness Index. { hereinafter, sometimes referred to as "YI"), high elastic modulus, good gas barrier properties, low water absorption or excellent resistance to aging by heating to meet the above criteria.

The relationship between the excellent color tone of the polyamide resins of the present invention and such a sulfur content has not been sufficiently explained, but such an excellent color tone is achieved by controlling the concentration of the sulfur atom to 1. at 200 ppm.

The diamine structural unit constituting the polyamide resins contains 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more of a unit derived from xylylenediamine (A-1) and / or bis. { aminomethyl) cyclohexane (A-2). The unit derived from xylylenediamine (A-1) preferably possesses a unit derived from m-xylylenediamine, a unit derived from p-xylylenediamine or both. The melting point or glass transition point, resistance to heating and crystallization ratio of the polyamide resins can be improved by the combination of a unit derived from m-xylylenediamine and a unit derived from p-xylylenediamine. The polyamide resins can exhibit an excellent elastic modulus and gas barrier properties by containing 70 mol% or more of the unit derived from xylylenediamine in the unit derived from a diamine component.

For the purpose of improving the crystallization ratio of the polyamide resins, the unit derived from p-xylylenediamine in the unit derived from a diamine component is preferably 20 mol% or more, more preferably 40 mol% or more, even more preferably 60% or more.

For the purpose of improving the flexibility of the polyamide resins, the unit derived from m-xylenediamine in the unit derived from a diamine component is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90% mol or more.

The unit derived from bis (aminomethyl) cyclohexane (A-2) preferably possesses a unit derived from 1,4-bis (aminomethyl) cyclohexane, a unit derived from 1,3-bis (aminomethyl) cyclohexane or both. The unit derived from bis (aminomethyl) cyclohexane is 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more. The polyamide resins can exhibit an excellent elastic modulus and gas barrier properties, a high glass transition temperature as well as resistance to aging by heating by containing 70 mol% or more of the unit derived from bis (aminomethyl) cyclohexane in the Diamine unit.

The crystallinity of the melting point can be regulated as appropriate by controlling the proportion between the unit derived from 1,4-bis (aminomethyl) cyclohexane and the unit derived from 1,3-bis (aminomethyl) cyclohexane when both are present. . 1,4-bis (aminomethyl) cyclohexane includes cis-1,4-bis (aminomethyl) cyclohexane and trans-1,4-bis (aminomethyl) cyclohexane as isomers, and 1,3-bis (aminomethyl) cyclohexane also includes cis- 1,3-bis (aminomethyl) cyclohexane and trans-1,3-bis (aminomethyl) cyclohexane as isomers, and the crystallinity of the polyamide resins can be conveniently adjusted by changing the cis / trans molar ratio in the unit derived from bis (aminomethyl) cyclohexane. A molar ratio of preferred isomer depends on the purpose of the application of the molding of a polyamide resin, that is, it depends on whether it is used for applications that require a high crystallinity or applications that require a low crystallinity or no crystallinity.

A molar ratio of the preferred isomer of 1,4-bis (aminomethyl) cyclohexane (A) depends on the purpose of the application of the molding of a polyamide resin, that is, it depends on whether it is used for applications requiring a high crystallinity. or applications that require low crystallinity or no crystallinity. For use in applications that require a high crystallinity, a preferred molar ratio of (cis / trans) isomer is 50/50 to 0/100 mol%, preferably 40/60 to 0/100 mol%, more preferably 30/70 mol 0/100% mol. Polyamide resins using 1,4-bis (aminomethyl) cyclohexane including 50 mol% or more of its trans-isomer are useful as resins for molding materials which have not only a high strength and high elastic modulus but also have a excellent retention of rigidity at high temperatures, durability at high temperatures and retention of mechanical development when absorbing water because the resins possess a high proportion of crystallization sufficient to provide sufficiently solidified and crystallized molding in molds.

For use in applications requiring low crystallinity or no crystallinity on the other hand, a preferred (cis / trans) isomer molar ratio is 100/0 to 50/50 mol%, preferably 100/0 to 60/40 mol%, more preferably 100/0 to 70/30 mol%. The polyamide resins which can be obtained by the use of 1,4-bis (aminomethyl) cyclohexane including 50 mol% or less of its trans-isomer possess a low crystallization ratio, resulting in polyamide resins without bleaching and with a High transparency even when they absorb water.

A molar ratio of the preferred isomer of 1,3-bis (aminomethyl) cyclohexane (A) depends on the purpose of the application of the molding of a polyamide resin, that is, it depends on whether it is used for applications requiring high crystallinity or Applications that require low crystallinity or no crystallinity. For use in applications requiring a high crystallinity, a preferred molar ratio of (cis / trans) isomer is 100/0 to 90/100% mol, preferably 100/0 to 93/7% mol, more preferably 100/0 to 95/5% mol. Polyamide resins using 1/3-bis (aminomethyl) cyclohexane including 90 mol% or more of its cis-isomer are useful as resins for the molding of materials having not only a high strength and a high elastic modulus but also an excellent retention of rigidity at high temperatures, durability at high temperatures and retention of mechanical development when they absorb water because they possess a high proportion of crystallization sufficient to provide molds sufficiently solidified and crystallized in molds.

For use in applications that require low crystallinity or no crystallinity on the other hand, a preferred (cis / trans) isomer molar ratio is 0/100 to 90/10 mol%, preferably 0/100 to 80/20 mol%, more preferably 0/100 to 70/30 mol%. The polyamide resins that can be obtained using 1,3-bis (aminomethyl) cyclohexane including 10 mole% or less of its trans-isomer possess a low crystallization ratio, resulting in polyamide resins without bleaching and with a high transparency even when they absorb water.

When the unit derived from a diamine component possesses both the unit derived from xylylenediamine (A-1) and the unit derived from bis (aminomethyl) cyclohexane (A-2), the total of both units is preferably 70 mol% or more.

Examples of units that can be derived from diamine-derivative other than xylylenediamine (Al) and bis (aminomethyl) cyclohexane (A-2) can include, but are not limited to, units derived from aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2- methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine and 2,4,4-trimethylhexamethylenediamine; alicyclic diamines such as 1,3-diaminocyclohexane, 1, -diaminocyclohexane, bis (4-aminociclohexane) methane, 2,2-bis (4-aminociclohexyl) propane, bis (aminomethyl) decane and bis (aminomethyl) tricyclodecane; diamines having an aromatic ring such as bis (4-aminophenyl) ether, p-phenylenediamine and bis (aminomethyl) naphthalene, etc.

On the other hand, 50 mol% or more of the structural unit of dicarboxylic acid constituting the polyamide resins of the present invention must be a unit derived from sebacic acid (B). If the quantity of the unit derived from sebacic acid (B) is less than 50 mol% of the structural unit derived from a dicarboxylic acid, the polyamide resins have a high moisture content, high water absorption (hygroscopy) and high density and tendency to deteriorate in resistance to aging by heating. The highest amounts of the unit derived from sebacic acid allow reduction in weight. The amount of the unit derived from sebacic acid is preferably from 60 to 100 mol%, more preferably from 70 to 100 mol%.

The structural units derived from dicarboxylic acids other than sebacic acid (B) in the polyamide resins preferably include units derived from dicarboxylic acids based on other straight chain aliphatic α, β-dicarboxylic acids containing from 4 to 20 carbon atoms, for example , units derived from aliphatic dicarboxylic acids such as adipic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, undecanic diacid, dodecanoic diacid, etc. Among them, the units derived from dicarboxylic acids other than sebacic acid are preferably units derived from adipic acid, undecanic diacid, dodecanoic diacid and the like, if these are present. Among them, an especially preferred dicarboxylic acid derived unit includes a unit derived from adipic acid. A suitable elastic modulus, water absorption and crystallinity can be obtained by the additional inclusion of a unit derived from adipic acid. The amount of the unit derived from adipic acid is more preferably 40 mol% or less, more preferably 30 mol% or less. Polyamide resins which additionally contain a unit derived from undecanic diacid or dodecanoic diacid are also preferred because they possess a lower specific gravity and the resulting moldings have a lower weight. The proportion of a unit derived from a straight-chain aliphatic O O, β-dicarboxylic acid containing from 4 to 20 carbon atoms other than sebacic acid is less than 50 mol%, preferably 40 mol% or less, if such a unit is present.

Units derived from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid may also be contained, and a plurality of these units may be contained.

In addition to the unit derived from the diamine component and the unit derived from the dicarboxylic acid component, the units derived from lactams such as e-caprolactam and laurolactam or aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid can also be contained as units of polymer constituting the polyamide resins in such a way that the benefits of the present invention are not affected.

The concentration of the sulfur atom of the polyamide resins is from 1 to 200 ppm, more preferably from 10 to 150 ppm, especially preferably from 20 to 100 ppm. When this is in the above ranges, not only the increase in YI of the polyamide resins during the preparation but also the increase in YI during the melt molding of the polyamide resins can be reduced in such a way that the YI of the The resulting moldings can be decreased.

The amount of phosphorus that inevitably exists in the polyamide resins in its industrial preparation as will be described below is preferably from 1 to 500 ppm, more preferably from 5 to 300 ppm, even more preferably from 10 to 200 ppm expressed as the concentration of phosphorus atom. If the phosphorus atom concentration is less than 1 ppm, the polyamide resins are prone to yellowing, and if it exceeds 500 ppm, polymerization control may be difficult due to an excessive amidation reaction during the synthesis of the resin. polyamide as will be described later.

The amount of sodium compounds typically existing in the polyamide resins in their industrial preparation as will be described below is preferably from 1 to 500 ppm, more preferably from 5 to 300 ppm, even more preferably from 10 to 200 ppm expressed as the concentration of sodium atom.

The ratio (P / Na) between the concentration of phosphorus atom (P) and the concentration of sodium atom (Na) in the polyamide resins is preferably from 0.4 to 0.9, more preferably from 0.4 to 0.8, even more preferably from 0.4 to 0.7. When it is in the above ranges, the degree of polymerization or molecular weight can easily be controlled due to the amidation reaction during the synthesis of the polyamide resins at an appropriate speed. Additionally, the increase in YI can be reduced when the polyamide resins are molded.

The number average molecular weight of the polyamide resins is preferably from 8,000 to 50,000, more preferably from 12,000 to 45,000, even more preferably from 15,000 to 40,000, especially from 20,000 to 38,000. When it is in such intervals, the fluidity is good in such a way that the malleability is good during the preparation of several moldings. If this is more than 50,000, the YI of the polyamide resins can be increased because an excessive thermal history must be applied during the synthesis of the polyamide resins. When this is in the above range, the fluidity of the resins is optimal during the molding processes in such a way that the retention in the apparatus can be reduced and the resulting molding can have a better quality with small inclusions such as carbon.

The average number of the molecular weight of a polyamide resin is calculated by equation (2) below: Average number of molecular weight = 2 x 1 '000, 000 / ([COOH] + [NH2]) (2) wherein [COOH] represents the concentration of the terminal carboxyl group in the polyamide resin (peq / g), and IN¾] represents the concentration of a terminal amino group in the polyamide resin (μ q / q).

As used herein, the concentration of a terminal amino group refers to the calculated value of the neutralization titers of a solution of polyamide resin dissolved in a mixed solution of phenol / ethanol with a solution of dilute aqueous hydrochloric acid, and the concentration of a terminal carboxyl group refers to the calculated value of neutralization titers of a solution of a polyamide resin dissolved in benzyl alcohol with a solution of aqueous sodium hydroxide or a solution of potassium hydroxide / benzyl alcohol.

The melting point of the polyamide resins should preferably be controlled in the range of 150 ° C to 320 ° C, more preferably 160 to 310 ° C, even more preferably 170 to 300 ° C, especially preferably 180 to 295. ° C, most preferably 180 to 290 ° C. The melting point is preferably in the above ranges because the processability tends to improve.

The glass transition temperature of the polyamide resins is preferably in the range of 50 to 130 ° C. The glass transition point is preferably in the above range because the barrier properties tend to improve.

As used herein, the melting point and glass transition of a polyamide resin refer to the melting point and glass transition that can be determined by differential scanning calorimetry (DSC) by casting a shows by heating once to eliminate the influence of thermal history on the crystallinity and then heating it again. Specifically, a sample is heated at a rate of 10 ° C / min from 30 ° C to a temperature equivalent to or greater than an expected melting point, and maintained at that temperature for 2 min, and then cooled to a ratio of 20 min. ° C / min at 30 ° C. Then, the sample is heated at a rate of 10 ° C / min at a temperature equivalent to or greater than the melting point, whereby the melting point and the glass transition point can be determined.

The polyamide resins preferably have a concentration of an amino terminal group of less than 100 μg /, more preferably from 5 to 75 μg / g, even more preferably from 10 to 50 eq / g, and a concentration of a carboxyl group terminal of less than 100 μß? ^, more preferably from 10 to 90 eq / g, even more preferably from 10 to 50 μeq g. Those having a concentration of an amino terminal group and a concentration of a terminal carboxyl group in the above ranges tend to show a stable viscosity during molding and improved processability.

The polyamide resins preferably have a molar ratio of the diamine component to the reacted dicarboxylic acid component (the number of moles of the diamine component reacted / the number of moles of the reacted dicarboxylic acid component) from 0.98 to 1.1, more preferably from 0.985 to 1, even more preferably from 0.99 to 0.999. Reaction molar ratios outside the range of 0.98 to 1.1 are not preferred because the average molecular weight number of the polyamide resins is less likely to decrease. Reaction molar ratios greater than 1.1 are not preferred, either because the polyamide resins possess excessive amino terminal groups, inviting a tendency to increase the turbidity of the resulting moldings or increase the possibility of production of gelled materials.

The molar reaction ratio (r) here is determined by the following equation: r = (1-cN-b (C-N)) / (1-cC + a (C-N)) where to: Mi / 2 b: M2 / 2 c: 18,015 Mi: the molecular weight of the diamine component (g / mol) M2: the molecular weight of the dicarboxylic acid component (g / mol) N: concentration of the terminal amino group (eq / g) C: concentration of the terminal carboxyl group (eq / g).

The polyamide resins preferably have a relative viscosity of 1.7 to 4.7, more preferably 2.05 to 4.3, even more preferably 2.45 to 3.9 as determined at a resin concentration of lg / 100 ce in 96% sulfuric acid at a temperature of 25 ° C. Such ranges are preferred because the malleability tends to improve.

The moisture content of the polyamide resins is preferably from 0.005 to 0.8% by mass, more preferably from 0.01 to 0.6% by mass, even more preferably from 0.02 to 0.5% by mass. If the moisture content is in the above ranges, the polyamide resin compositions having a stable quality can be easily prepared because the molecular weight loss can be reduced when these are prepared by kneading-melting the polyamide resins with additive components as appropriate, for example. When the polyamide resins have been prepared by solid phase polymerization, a preferred moisture content is preferably 0.005 to 0.2 mass%, more preferably 0.01 to 0.1 mass%, even more preferably 0.02 to 0.08 mass%. If it is in the above ranges, the polyamide resins can be stably molded into films, tubes, bottles or the like without increasing or decreasing the viscosity. On the other hand, the resulting moldings also tend to have a good appearance because the appearance of the product is not damaged due to bubbles or the like during molding.

The process for the preparation of polyamide resins of the present invention is not specifically limited, but can be developed using any polymerization method and conditions. For example, polyamide resins can be prepared by heating a nylon salt consisting of a diamine component (e.g., m-xylylenediamine, bis (aminomethyl) cyclohexane) and a carboxylic acid component (e.g., sebacic acid) under pressure in the presence of water to polymerize it in a state of fusion while the added water and condensed water is removed.

The polyamide resins can also be prepared by the direct addition of a diamine component (m-xylylenediamine, bis (aminomethyl) cyclohexane, etc.) to a carboxylic acid component (sebacic acid, etc.) in a state of fusion and applying polycondensation under atmospheric or elevated pressure. In the latter case, the polycondensation proceeds by the continuous addition of the diamine component to the dicarboxylic acid component while the reaction system is heated to a reaction temperature not less than the melting points of the oligoamide and polyamide produced for keep the reaction system in a homogeneous liquid state.

During the polycondensation of the polyamide resins, a small amount of monoamine or monocarboxylic acid can be added as a molecular weight modifier.

The polyamide resins can also be polycondensed by solid phase polymerization after they are prepared by melt polymerization. The solid phase polymerization is not specifically limited, but can be developed using any polymerization method and conditions.

The sebacic acid (B) preferably has here a sulfur atom concentration of 1 to 200 ppm, more preferably 10 to 150 ppm, especially preferably 20 to 100 ppm. When this is in the above range, the increase in YI can be reduced during the synthesis of the polyamide resins. The increase in YI during the melt molding of the polyamide resins can also be reduced such that the YI of the resulting moldings can be decreased.

On the other hand, sebacic acid (B) preferably has a sodium atom concentration of 1 to 500 ppm, more preferably 10 to 300 ppm, especially preferably 20 to 200 ppm. When this is in the above range, the polyamide resins are synthesized with a good reactivity and easily controlled in an appropriate molecular weight range and the amount of alkali metal compounds used for the control of the reaction rate of the amidation described. later it can be reduced. On the other hand, the increase in viscosity during the melt molding of the polyamide resins can be reduced in such a way that the workability is improved and the carbon can be prevented during molding, whereby the resulting moldings tend to have a good quality. Additionally, polyamide resins tend to be less likely to be deposited as degraded resins on a mold when they are composed of glass fillers or the like.

Such sebacic acid (B) is preferably derived from a plant. The polyamide resins containing a unit derived from sebacic acid < B) of a plant origin as a structural unit having a low YI without the addition of some antioxidant and the resulting moldings also have a low YI because the sebacic acid derived from a plant contains impurities such as sulfur compounds and sodium compounds . The sebacic acid derived from a plant (B) is preferably used without the excessive purification of impurities. The elimination of the need for excessive purification is also advantageous in terms of costs.

The purity of the sebacic acid derived from a plant (B) is preferably from 99 to 100% by mass, more preferably from 99.5 to 100% by mass, even more preferably from 99.6 to 100% by mass. These ranges are preferred, because the resulting polyamide resins possess a good quality and the polymerization is not affected.

For example, the amount of dicarboxylic acids such as 1, 10-decamethylenedicarboxylic acid contained in sebacic acid (B) is preferably from 0 to 1% by mass, more preferably from 0 to 0.7% by mass, even more preferably from 0 to 0.6. % in mass. These ranges are preferred, because the resulting polyamide resins possess a good quality and the polymerization is not affected.

The amount of monocarboxylic acids such as octanoic acid, nonanoic acid and undecanoic acid contained in the sebacic acid (B) is preferably 0 to 1% by mass, more preferably 0 to 0.35% by mass, even more preferably 0 to 0.4. % in mass. These ranges are preferred, because the resulting polyamide resins possess a good quality and the polymerization is not affected.

The shade (APHA) of the sebacic acid (B) is preferably 100 or less, more preferably 75 or less, even more preferably 50 or less. These ranges are preferred, because the resulting polyamide resins have a low YI. As used in this document, APHA can be determined using the Standard Methods for the Analysis of Fats, Oils and Related Materials defined by the Japan Oil Chemist's Society.

During the preparation of the polyamide resins, hypophosphite compounds (also known as phosphinate compounds or phosphonite compounds) or phosphite compounds (also known as phosphonate compounds) or their like are typically added as antioxidants (heat stabilizers) in the polycondensation stage in the melting state or the preparation stage of the starting materials (aqueous nylon salt solutions) for the purpose of improving the stability processes during molding and preventing discoloration of the polyamide resins or by catalyzing the nesting reaction. These phosphate antioxidants are oxidized in salts of phosphorous acid or salts of phosphoric acid in such a way that the oxygen is removed from the polyamide resin being polycondensed, thereby preventing the oxidative degradation of the polyamide molecules.

The amount of phosphorus thus inevitably existing in the polyamide resins of the present invention in its industrial preparation is from 1 to 500 ppm, more preferably from 5 to 300 ppm, even more preferably from 10 to 200 ppm expressed as the concentration of carbon atom. phosphorus, as previously described. If the concentration of the phosphorus atom is less than 1 ppm, the polyamide resins are prone to yellowing, and if it exceeds 500 ppm, it may be difficult to control the polymerization due to the excessive amidation reaction during the synthesis of the resins. polyamide.

Specific examples of the hypophosphite compounds as antioxidants include hypophosphorous acid; metal salts of hypophosphorous acid such as sodium hypophosphite, potassium hypophosphite and lithium hypophosphite; hypophosphite compounds such as ethyl hypophosphite, dimethylphosphinic acid, phenylmethylphosphonic acid, phenylphosphorous acid and ethyl phenylphosphonite; metal salts of phenylphosphorous acid such as sodium phenylphosphonite, potassium phenylphosphonite and lithium phenylphosphonite, etc.

Specific examples of phosphite compounds include phosphorous acid, pyrophosphorous acid; metal salts of phosphorous acid such as sodium hydrogen phosphite and sodium phosphite; phosphite compounds such as triethyl phosphite, triphenyl phosphite, ethylphosphonic acid, phenylphosphonic acid and diethyl phenylphosphatic; metal salts of phenylphosphonic acid such as sodium ethylphosphonate, potassium ethylphosphonate, sodium phenylphosphonate, potassium phenylphosphonate and lithium phenylphosphonate, etc.

Among these, the preferred antioxidants are metal salts of hypophosphorous acid such as sodium hypophosphite, potassium hypophosphite and lithium hypophosphite, especially sodium hypophosphite in view of the promotion effect of the polymerization reaction of polyamide resins and the effect of prevention of discoloration.

The polycondensation of the polyamide resins can be developed in the presence of a phosphorus-containing compound, as described above. However, if the phosphorus-containing compound is used excessively, the speed of the amidation reaction is thus promoted that the polymerization becomes difficult to control and coal can be produced during the molding of the polyamide resins.

In this way, an alkali metal compound is often used at the same time in order to control the speed of the amidation reaction. The alkali metal compound is used in an amount such that the number of moles of the alkali metal compound divided by the number of moles of the phosphorus-containing compound is typically in the range of 0.5 to 1, preferably 0.55 to 0.95, inclusive more preferably 0.6 to 0.9. When the amount is in the above range, the polycondensation takes place at an appropriate speed and the polyamide resins having a low YI and an excellent quality can be obtained.

The alkali metal compounds typically used are alkali metal hydroxides and alkali metal acetates, preferably sodium hydroxide and sodium acetate.

The amount of sodium compounds inevitably existing in this way in the polyamide resins of the present invention in their industrial preparation is preferably from 1 to 500 ppm, more preferably from 5 to 300 ppm, even more preferably from 10 to 200 ppm expressed as the concentration of sodium atom, as previously described. The sodium compounds can be derivatives of sebacic acid (B) or both of sebacic acid (B) and of the alkali metal compounds described above.

The ratio (P / Na) between the concentration of the phosphorus atom (P) and the concentration of the sodium atom (Na) in the polyamide resins is preferably 0.4 to 0.9, more preferably 0.4 to 0.8, even more preferably 0.4 to 0.7, as previously described. When it is in the above ranges, the degree of polymerization or the molecular weight can easily be controlled due to the amidation reaction during the synthesis of the polyamide resins which progresses at the appropriate speed. Additionally, the increase in YI can be reduced when the polyamide resins are molded.

The polyamide resins of the present invention can be combined with resins other than the polyamide resins of the present invention to form resin compositions to the extent that the benefits of the present invention are not affected. Specific examples include polyamide resins other than the polyamide resins of the present invention, polyester resins, polycarbonate resins, polyphenylene ester resins, polyacetal resins, polyimide resins, polyurethane resins, acrylic resins, polyacrylonitrile, ionomers, copolymers of ethylene-vinyl acetate, fluorine resins, vinyl alcohol copolymers such as ethylene-vinyl alcohol, biodegradable resins and the like, and these may be used alone or as a mixture of two or more of them.

Additionally, the polyamide resins of the present invention can be combined with various additives as appropriate to form resin compositions as long as the objective of the present invention is not affected. Specifically, organic stabilizers such as phosphorus stabilizers, hindered phenol light stabilizers, hindered amine light stabilizers, organic sulfur stabilizers, oxanilide stabilizers and aromatic secondary stabilizers of the amine; inorganic stabilizers such as copper compounds and halides; inorganic fillers such as glass fillers (glass fibers, ground glass fibers (ground fibers), glass flakes, glass beads, etc.), calcium silicate fillers (wollastonite, etc.) , mica, talc, kaolin, potassium titanate whiskers, boron nitride and carbon fibers; crystal nucleation agents such as talc and boron nitride; materials for improving hydrolysis resistance such as carbodiimide compounds; conductive agents; lubricants; plasticizers; release agents; pigments; dyes; dispersing agents; antistatic agents; UV absorbers; impact resistance enhancers; flame retardants; and other well-known additives may be added, for example.

The polyamide resins of the present invention can be formed into molded articles in various forms by previously known molding processes. Examples of molding processes include, for example, injection molding, blow molding, extrusion molding, compression molding, vacuum molding, pressure molding, direct blow molding, rotary molding, interleaving molding and two color molding. .

Known molding processes such as injection molding, blow molding, extrusion molding, compression molding, blow molding and drawing and vacuum molding can be applied to the polyamide resins of the present invention. These can be molded as engineering plastics not only in molded blocks but also in other forms such as films, sheets, hoses, empty containers, fibers and pipes in such a way that they can be used properly for industrial resources, industrial materials, household goods , etc.

EXAMPLES The following examples and comparative examples further illustrate the present invention, but the present invention should not be construed as being limited to these examples.

The analyzes for evaluation in the present invention were developed by the following methods. (1) Concentration of the sulfur atom (expressed in ppm) The sebacic acid or the polyamide resin were compressed into tablets through a press and subjected to X-ray fluorescence (XRF) analysis. The XRF analyzer used was the ZSX Primus X-ray fluorescence spectrometer available from Rigaku Corporation eguided with an Rh tube (4 kw). A PP film was used as a film for the analysis window and EZ scanning measurements were developed in a vacuum atmosphere. The irradiated areas are 30 mm f. (2) Concentration of the sodium atom and concentration of the phosphorus atom (expressed in ppm) The concentration of the sodium atoms and the concentration of the phosphorus atoms contained in the sebacic acids and the polyamide resins were analyzed by the use of an atomic absorption spectrometer (available from SHIMADZU Corporation under the factory brand of AA- 6650) and an ICP emission spectrometer (available from SHIMADZU Corporation under the trademark ICPE-9000) subsequently, sebacic acid or polyamide resins were degraded by microwaves in nitric acid. (3) Acid content 1,10-10 decamethylenedicarboxylic acid (abbreviated as "DMDC") (expressed in% by mass) The DMDC in sebacic acid was analyzed qualitatively / quantitatively by GC / MS after derivatization (to methyl esters). A specific procedure is as follows: (a) Weigh 8 mg of sebacic acid in a 1 ml reaction vial. (b) Add 0.5 ml of a solution of boron trifluoride-methanol complex in methanol (for GC assay: 9 n 17 to 15% available from ako Puré Chemical Industries) and place a lid over the vial. (c) Heat the vial in a controlled block bath at 100 ° C for 1 hr, and then allow it to cool to room temperature. 5 (d) Transfer the reaction solution to a 5 ml reaction vial, and add 1 ml of chloroform (for atomic absorption spectroscopy available from JUNSEI Chemical Co.) and 2 ml of pure water. (e) Shake the vial for 5 min, and then let it stand for 30 min. (f) Collect the organic layers (lower layers) by means of a syringe and repeat steps (d) and (e). (g) Collect the organic layers (lower layers) by syringe and subject them to GC / MS analysis. (h) Qualitatively analyze the components of an MS spectrum and calculate the DMDC content (% by mass) from the TIC peak areas.

The conditions for GC / MS analysis are as follows: GC Equipment: 6890N from Agilent MS Team: Agilent 5975 Inert MDS Column: CP-Sil 8CB for amines, 30 m x 0.25 mm? x 0.25 \ i t Transporter gas: helium 1 ml / min Oven temperature: sustained at 80 ° C for 5 min, then raised to 10 ° C / min at 300 ° C and sustained at 300 ° C for 13 min.

Injection Division (50: 1), inlet temperature 300 ° C, 1 μ? Interface temperature 300 ° C Ion source temperature 250 ° C Pole temperature Q 150 ° C Mass Interval (m / z) 40 to 800 Ionization Energy 70 eV (4) Melting point (Tm) and glass transition point (Tg) of polyamide resins The melting point (Tm) was determined by differential scanning calorimetry (DSC) using a DSC-60 (available from SHIMADZU CORPORATION) from the temperature to the upper part of the endothermic peak when a sample of polyamide resin was melted by heating from 30 ° C to a temperature equivalent to or greater than an expected melting point at a ratio of 10 ° C / min. The molten sample was cooled on dry ice and then heated to a temperature equivalent to or greater than the melting point at a rate of 10 ° C / min to determine the glass transition point (Tg). (5) Concentration of the terminal amino group ([NH2]) In 30 ml of a mixed solution of phenol / ethanol (4: 1) 0.3 g of each of the polyamide resins obtained by the previously described methods was dissolved with stirring at 20 to 30 ° C, and this solution was titrated with 0.01N hydrochloric acid to determine the concentration. (6) Concentration of the terminal carboxyl group ([COOH]) In 30 ml of benzyl alcohol, 0.1 g of each of the polyamide resins obtained by the methods described above were dissolved at 200 ° C, and 0.1 ml of a red solution of phenol were added in the range of 160 ° C to 165 ° C. ° C. This solution was titrated with a titration solution of 0.132 g of KOH in 200 ml of benzyl alcohol (0.01 mol / 1 expressed as KOH content) to determine the concentration.

Proportion of the concentration of the terminal amino group to the concentration of the terminal carboxyl group ([NH2] / [COOH]) The ratio was calculated from the concentration of the terminal amino group and the concentration of the terminal carboxyl group determined by the methods described above. (7) Average number of molecular weight The average number of the molecular weight was calculated by the following equation from the values of the concentration of the terminal amino group [H2]. { xeq / g) and the concentration of the terminal carboxyl group [COOH] (eq / q) determined by the neutralization titers described above.

Average number of molecular weight 2 x 000, 000 / ([COOH] + [NH2]). (8) Reaction molar ratio The molar reaction ratio was determined by the following equation: 5 r = (l-cN-b (C-N)) / (l-cC + a (C-N)) where to: Mi / 2 b: M2 / 2 c: 18,015 Mi: the molecular weight of the diamine component (g / mol) 10 M2: the molecular weight of the dicarboxylic acid component (g / mol) N: concentration of the terminal amino group (eq / g) C: concentration of the terminal carboxyl group (eq / g). fifteen Preparation of sebacic acids In accordance with the method described in "Journal of Oleo Science 7, 133 (1958)", the sebacic acids (SA1) - (SA4) possessing the sulfur contents, sodium contents and DMDC contents described in Table 1 were on prepared by alkaline fusion of ricinoleic acid in sesame oil extracted from sesame of various origins. The concentrations of the sulfur atom, the concentrations of the sodium atom and the DMDC contents (% by mass) of the sebacic acids (SA1) - (SA4) are 5 shown in Table 1.

Examples 1-7, Comparative Example 1 Example 1 A reaction vessel equipped with an agitator, a partial condenser, a total condenser, a thermometer, a dropping funnel and a nitrogen inlet as well as a filament mold was loaded with 12.135 g (60 mol) of sebacic acid (SAI) , and purged thoroughly with nitrogen and then heated to 170 ° C while the interior of the system is stirred under a small amount of nitrogen gas stream.

To this, 8,172 g (60 mol) of m-xylylenediamine (MXDA) was added by dripping with stirring and the interior of the system was continuously heated while the condensed water generated was removed to the outside of the system. Subsequently, upon completion of the drip addition of m-xylylenediamine, the melt polymerization reaction was continued for 40 min at an internal temperature of 260 ° C.

Subsequently, the interior of the system was pressurized with nitrogen, and the polymer was collected from the filament mold and pelletized to provide approximately 22 kg of a polyamide resin. The resulting polyamide resin has a melting point of 190 ° C and a glass transition point of 60 ° C.

The characteristics of this sebacic acid and the results of the evaluation of the polyamide resin are described in Table 1.

Example 2 A polyamide resin was synthesized in the same manner as in Example 1 except that 9.3149 g of sodium hypophosphite monohydrate (NaH2P02 · H20) (150 ppm expressed as the concentration of the phosphorus atom in the polyamide resin) and 4.8301 g of sodium acetate were introduced into a reaction vessel in addition to sebacic acid (SAI). The molar ratio of sodium acetate / sodium hypophosphite monohydrate is 0.67. The resulting polyamide resin has a melting point of 190 ° C and a glass transition point of 60 ° C.

Example 3 and Example 4 The polyamide resins were synthesized in the same manner as in Example 1 and Example 2, respectively, except that the sebacic acid was replaced by SA2 having the characteristics described in Table 1. The results of the evaluation of these resins of polyamide are described in Table 1. The resulting polyamide resins possess melting points of 190 ° C and 190 ° C, respectively, and glass transition points of 60 ° C and 60 ° C, respectively.

Example 5 A polyamide resin was synthesized in the same manner as in Example 1 except that the sebacic acid was replaced by SA3 having the characteristics described in Table 1 and that 3.1050 g of sodium hypophosphite monohydrate (NaH2P02.H20) (50 ppm expressed as the concentration of the phosphorus atom in the polyamide resin) and 1.6100 g of sodium acetate were used. The resulting polyamide resin had a melting point of 190 ° C and a glass transition point of 60 ° C.

Example 6 A polyamide resin was synthesized in the same manner as in Example 1 except that m-xylylenediamine (MXDA) was replaced by a 6: 4 diamine mixture of m-xylylenediamine (MXDA) and p-xylylenediamine (PXDA) and that 12.4198 g of sodium hypophosphite monohydrate (NaH2P02, H20) (200 ppm expressed as the concentration of the phosphorus atom in the polyamide resin) and 6.4402 g of sodium acetate were used. The resulting polyamide resin has a melting point of 221 ° C and a glass transition point of 64 ° C Example 7 A reaction vessel equipped with an agitator, a partial condenser, a total condenser, a thermometer, a drip device and a nitrogen inlet as well as a filament mold was loaded with 8950 g (44 mol) of sebacic acid (SAI) accurately weighed, 13.7401 g of sodium hypophosphite monohydrate (300 ppm expressed as the concentration of the phosphorus atom in the polyamide resin), and 10.6340 g of sodium acetate. The molar ratio between sodium hypophosphite and sodium acetate is 1.0. The interior of the reaction vessel was flushed thoroughly with nitrogen and then pressurized with nitrogen at 0.3 MPa and heated to 160 ° C with stirring to homogenously fuse the sebacic acid. Then, 6026 g (44 mol) of p-xylylenediamine (PXDA) were added by dripping with stirring for about 170 min. During and then, the internal temperature was continuously raised to 281 ° C. During the step of addition by dripping, the pressure was controlled at 0.5 MPa and the generated water was removed out of the system through the partial condenser and the total condenser. The temperature in the partial condenser was controlled in the range of 145 to 147 ° C. After completion of the dropwise addition of p-xylylenediamine, the pressure was reduced to a rate of 0.4 MPa / hr under atmospheric pressure for 60 min. During and then, the internal temperature rises to 299 ° C. Then, the pressure was decreased to a ratio of 0.002 MPa / min to 0.08MPa for about 20 min. Then, the reaction was continued at 0.08 MPa until the torque of the agitator reached a predetermined value. The reaction period at 0.08 MPa was 10 min. Then, the interior of the system was pressurized with nitrogen, and the polymer was collected from the filament mold and pelletized to provide approximately 13 kg of a polyamide resin. The resulting polyamide resin has a melting point of 288 ° C and a glass transition point of 75 ° C.

Comparative example A polyamide resin was synthesized in the same manner as in Example 1 except that the sebacic acid was replaced by SA4 having the characteristics described in Table 1. The resulting polyamide resin possesses a melting point of 190 ° C and a transition glass of 60 ° C.

The evaluation results of the polyamide resins obtained above are described in Table 1.E1 YI value, flexural modulus of elasticity and gas barrier properties were evaluated as follows. (i) YI Value The obtained polyamide resins were used in the 100T injection molding machine available from FANUC CORPORATION under conditions of a controlled cylinder temperature at the melting point of each polyamide resin plus 30 ° C and a mold temperature of 80 ° C. to prepare a plate having a thickness of 3 mm, which was analyzed in accordance with JIS K-7105 using the spectrophotometer model SE2000 available from NIPPON DENSHOKU INDUSTRIES CO., LTD., in reflectance mode. (ii) Flexural modulus of elasticity (expressed in GPa) The obtained polyamide resins were used in the 100T injection molding machine available from FANÜC CORPORATION under controlled cylinder temperature conditions at the melting point of each polyamide resin plus 30 ° C and a mold temperature of 80 ° C for prepare a specimen having a thickness of 3 iran. The specimen obtained was crystallized at 150 ° C for 1 hr and the flexural modulus of elasticity (GPa) was determined in accordance with JIS K7171 using a Strograph available from Tokyo Seiki Kogyo., Ltd. at a temperature of 23 ° C and a humidity of 50% RH. (iii) Gas barrier properties (expressed in ce .mm / m2, day atm) The obtained polyamide resins were fed to a single screw extruder having a cylinder diameter of 30 mm and equipped with a flat mold (PTM-30 available from PLABOR Research Laboratory of Plastics Technology Co., Ltd.). A material similar to a film was extruded through the flat mold under conditions of a controlled cylinder temperature at the melting point of each polyamide resin plus 30 ° C and a screw rotation speed of 30 rpm, and solidified on a cooled roll to provide a film having a thickness of 100 μp ?.

The resulting film was used to determine the oxygen transmission rate (cc.mm/m2.día.atm) of the film in accordance with JIS K7126 under an atmosphere of 23 ° C, 75% RH using OX-TRAN2 / 21 available from odern Controls, Inc. Lower values show better gas barrier properties.

Table 1 Examples 8-14, Comparative Examples 2-3 Preparation of sebacic acids In accordance with the method described in "Journal of Oleo Science 7, 133 (1958)", the sebacic acids (SA11) - (SA13) having the contents of sulfur, sodium contents and DMDC contents described in Table 2 were prepared by alkaline fusion of ricinoleic acid in sesame oil extracted from sesame of various origins.

TA grade sebacic acid available from Itoh Oil Chemicals Co., Ltd. was used as sebacic acid derived from sesame oil (SA14). Additionally, the sebacic acid derived from the synthetic oil component (adipic acid) (SA15) was prepared according to the method described in JPB S57-60327.

The concentrations of the sulfur atom, the concentrations of the sodium atom and the DMDC contents of the sebacic acids (SAI 1) - (SA15) are shown in Table 2.

Example 8 A reaction vessel equipped with a stirrer, a partial condenser, a total condenser, a thermometer, a dropping funnel and a nitrogen inlet as well as a filament mold was charged with 12.135 g (60.00 mol) of sebacic acid (SA11) , and purged thoroughly with nitrogen and then heated to 170 ° C while the interior of the system is stirred under a small amount of nitrogen gas stream.

To this, 8.413.8 g (60.00 mol) of 1,4-bis (aminomethyl) cyclohexane (hereinafter, sometimes referred to as "14BAC", cis / trans molar ratio: 20/80) was added by dripping. Mitsubishi Gas Chemical Company, Inc. With stirring and the interior of the system was continuously heated while the condensed water generated was removed from the system. After completion of the dropwise addition of 1,4-bis (aminomethyl) cyclohexane, the melt polymerization reaction was continued for 40 min at an internal temperature of 300 ° C.

Subsequently, the interior of the system was pressurized with nitrogen, and the polymer was collected from the filament mold and pelletized to provide approximately 22 kg of a polymer resin. The resulting polymer resin had a melting point of 288 ° C and a glass transition point of 89 ° C.

Example 9 A polyamide resin was synthesized in the same manner as in Example 8 except that 9,439 g of sodium hypophosphite monohydrate (NaH2P02.H20) (150 ppm per mass expressed as the concentration of the phosphorus atom in the polyamide resin) and 4.8945 g of sodium acetate were introduced into the reaction vessel in addition to the sebacic acid (SA11). The molar ratio of sodium acetate / sodium hypophosphite monohydrate is 0.67. The resulting polyamide resin had a melting point of 288 ° C and a glass transition point of 89 ° C.

Example 10 and Example 11 The polyamide resins were synthesized in the same manner as in Example 8 as for Example 10 and in the same manner as in Example 9 as for Example 11 except that the sebacic acid was replaced by SA12 having the characteristics described in FIG. Table 2 and that the cis / trans molar ratio of 1,4-bis (aminomethyl) cyclohexane was changed.

The results of the evaluation of these polyamide resins are described in Table 2. The resulting polyamide resins have melting points of 296 ° C and 261 ° C, respectively, and glass transition points of 91 ° C and 90 ° C, respectively.

Example 12 A polyamide resin was synthesized in the same manner as in Example 8 except that the sebacic acid was replaced with SA13 having the characteristics described in Table 2 and that 3.1463 g of sodium hypophosphite monohydrate (NaH2P02.H20) (50 ppm mass, expressed as the concentration of the phosphorus atom in the polyamide resin) and 1.6351 g of sodium acetate, were used. The resulting polyamide resin has a melting point of 288 ° C and a glass transition point of 89 ° C.

Example 13 A polyamide resin was synthesized in the same manner as in Example 8 except that 1,4-bis (aminomethyl) cyclohexane was replaced with a 95: 5 diamine mixture of cis- and trans-isomers and that 12.5853 g of monohydrate of sodium hypophosphite (NaH2P02, H20) (200 ppm in mass expressed as the concentration of the phosphorus atom in the polyamide resin) and 6,526 g of sodium acetate were used. The resulting polyamide resin had a melting point of 207 ° C and a glass transition point of 87 ° C.

Example 14 A reaction vessel equipped with an agitator, a partial condenser, a total condenser, a thermometer, a drip device and a nitrogen inlet as well as a filament mold was charged with 8950 g (44.25 mol) of sebacic acid (SA11) accurately weighed, 13.9232 g of sodium hypophosphite monohydrate (300 ppm by mass expressed as the concentration of the phosphorus atom in the polyamide resin), and 10.7757 g of sodium acetate. The molar ratio between sodium hypophosphite and sodium acetate is 1.0. The interior of the reaction vessel was flushed thoroughly with nitrogen and then pressurized with nitrogen at 0.3 MPa and heated to 160 ° C with stirring to homogenously fuse the sebacic acid. So, 6174.5 g (44.03 mol) of 1, -bis (aminomethyl) cyclohexane were added by dropping with stirring for about 170 min. During and then, the internal temperature was continuously raised to 291 ° C. During the drip addition step, the pressure was controlled at 0.5 MPa and the water generated was removed from the system by means of the partial condenser and the total condenser. The temperature in the partial condenser was controlled in the range of 145 to 147 ° C. After completing the addition by dripping 1,4-bis (aminomethyl) cyclohexane, the pressure was decreased at a rate of 0.4 MPa / hr under atmospheric pressure for about 60 min. During and then, the internal temperature rose to 300 ° C. Subsequently, the pressure was reduced to a ratio of 0.002 MPa / min to 0.08 MPa for about 20 min. Subsequently, the reaction was continued at 0.08 MPa until the torque of the agitator reached a predetermined value. The reaction period at 0.08 MPa was 10 min. Subsequently, the interior of the system was pressurized with nitrogen, and the polymer was collected from the filament mold and pelleted to provide approximately 13 kg of a polyamide resin. The resulting polyamide resin had a melting point of 288 ° C and a glass transition point of 89 ° C.

Comparative examples 2-3 The polyamide resins were synthesized in the same manner as in Example 8 except that the sebacic acid was replaced by SA14 and SA15 having the characteristics described in Table 2. The resulting polyamide resins both had a melting point of 288 ° C. and a glass transition point of 89 ° C.

The results of the evaluation of the polyamide resins obtained above are described in Table 2. The YI value, flexural modulus of elasticity and retention of tensile strength were evaluated as follows. (i) YI Value The obtained polyamide resins were vacuum dried at 150 ° C for 5 hrs and subsequently processed in the 100T injection molding machine available from FANUC CORPORATION under conditions of a controlled cylinder temperature at the melting point of each polyamide resin plus 25 ° C and a mold temperature of 30 ° C to prepare a plate having a thickness of 3 mm, which was analyzed in accordance with JIS K-7105 using the spectrophotometer model SE2000 available from NIPPON DENSHOKU INDUSTRIES CO., LTD. in reflectance mode. (ii) Flexural modulus of elasticity (expressed in GPa) The obtained polyamide resins were dried under vacuum at 150 ° C for 5 hrs and then processed in the 100T injection molding machine available from FANUC CORPORATION under the condition of a controlled cylinder temperature at the melting point of each polyamide resin plus 25 ° C and at a mold temperature of 30 ° C to prepare a specimen having a thickness of 3 mm. The specimen obtained was crystallized at 150 ° C for 1 hr and the flexural modulus of elasticity (GPa) was determined in accordance with JIS K7171 using Strograph available from Toyo Seiki Kogyo Co. , Ltd. at a temperature of 23 ° C and a humidity of 50% RH. (iii) Aging resistance test by heating (retaining the tensile strength) The obtained polyamide resins were dried under vacuum at 150 ° C for 5 hrs and then processed in the injection molding machine "SE50" available from Sumimoto Heavy Industries, Ltd. under conditions of a controlled cylinder temperature at the melting point of each polyamide resin plus 25 ° C and a mold temperature of 30 ° C to prepare a specimen (ISO specimen having a thickness of 4 mm).

The resulting specimen was stored in the atmosphere at 150 ° C and its tensile strength (MPa) was determined in accordance with JIS K7113.

The tensile strength after storage at 150 ° C for 24 hrs was divided by tensile strength after storage at 150 ° C for 1 hr to determine the tensile strength retention (%).

Table 2 Examples 15-21, Comparative Examples 4-5 Example 15 A reaction vessel equipped with a stirrer, a partial condenser, a total condenser, a thermometer, a dropping funnel and a nitrogen inlet as well as a filament mold was charged with 12.135 g (60.00 mol) of sebacic acid (SA11) , and purged thoroughly with nitrogen and then heated to 170 ° C while the interior of the system is stirred under a small amount of nitrogen gas stream.

To this, 8.413.8 g (60.00 mol) of 1,3-bis (aminomet i1) cyclohexane (BAC molar ratio cis / trans: 74/26) was added by dripping available from Mitsubishi Gas Chemical Company, Inc. With stirring and stirring. The interior of the system was heated continuously while the condensed water generated was removed from the system. After the addition was completed by dropping 1,3-bis (aminomethyl) cyclohexane, the melt polymerization reaction was continued for 40 min at an internal temperature of 240 ° C. Subsequently, the interior of the system was pressurized with nitrogen, and the polymer was collected from the filament mold and pelletized to provide approximately 22 kg of a polyamide resin. The resulting polyamide resin had a melting point of 189 ° C and a glass transition point of 84.5 ° C.

Example 16 A polyamide resin was synthesized in the same manner as in Example 1 except that 9,439 g of sodium hypophosphite monohydrate (NaH2P02-H20) (150 ppm per mass expressed as the concentration of the phosphorus atom in the polyamide resin) and 4.8945 g of sodium acetate were introduced into the reaction vessel in addition to the sebacic acid (SAll). The molar ratio of sodium acetate / sodium hypophosphite monohydrate is 0.67. The resulting polyamide resin had a melting point of 189 ° C and a glass transition point of 84.5 ° C.

Example 17 and Example 18 The polyamide resins were synthesized in the same manner as in Example 15 as for Example 17 and in the same manner as in Example 15 as for Example 17 except that the sebacic acid was replaced by SA12 having the characteristics described in Table 3 and that the cis / trans molar ratio of 1,3-bis (aminomethyl) cyclohexane was changed. The results of the evaluation of these polyamide resins are described in Table 3. The resulting polyamide resins had melting points of 204 ° C and 204 ° C, respectively, and glass transition points of 86 ° C and 86 ° C, respectively.

Example 19 A polyamide resin was synthesized in the same manner as in Example 15 except that the sebacic acid was replaced with SA13 having the characteristics described in Table 3 and that 3.1463 g of sodium hypophosphite monohydrate (NaH2P02 .H? 0) ( 50 ppm by mass expressed as the concentration of the phosphorus atom in the polyamide resin) and 1.6351 g of sodium acetate were used. The resulting polyamide resin has a melting point of 189 ° C and a glass transition point of 84.5 ° C.

Example 20 A polyamide resin was synthesized in the same manner as in Example 15 except that 1,3-bis (aminomethyl) cyclohexane was replaced with a mixture of diamine 96: 4 of cis- and trans-isomers and that 12.5853 g of monohydrate of sodium hypophosphite (NaH2PC > 2 · H20) (200 ppm by mass expressed as the concentration of the phosphorus atom in the polyamide resin) and 6,526 g of sodium acetate were used. The resulting polyamide resin had a melting point of 209 ° C and a glass transition point of 88 ° C.

Example 21 A reaction vessel equipped with an agitator, a partial condenser, a total condenser, a thermometer, a drip device and a nitrogen inlet as well as a filament mold was charged with 8950 g (44.25 mol) of sebacic acid (SA11) accurately weighed, 13.9232 g of sodium hypophosphite monohydrate (300 ppm by mass expressed as the concentration of the phosphorus atom in the polyamide resin), and 10.7757 g of sodium acetate. The molar ratio between sodium hypophosphite and sodium acetate is 1.0. The interior of the reaction vessel was flushed thoroughly with nitrogen and then pressurized with nitrogen at 0.3 MPa and heated to 160 ° C with stirring to homogenously fuse the sebacic acid. Then, 6174.5 g (44.03 mol) of 1,3-bis (aminome il) cyclohexane were added by dripping with stirring for about 170 min. During and then, the internal temperature was continuously raised to 235 ° C. During the drip addition step, the pressure was controlled at 0.5 MPa and the water generated was removed from the system by means of the partial condenser and the total condenser. The temperature in the partial condenser was controlled in the range of 145 to 147 ° C. After completion of the dropwise addition of 1,3-bis (aminomethyl) cyclohexane, the pressure was decreased to a rate of 0.4 MPa / hr under atmospheric pressure for about 60 min. During and then, the internal temperature rose to 240 ° C. Subsequently, the pressure was reduced to a ratio of 0.002 MPa / min to 0.08 MPa for about 20 min.

Subsequently, the reaction was continued at 0.08 MPa until the torque of the agitator reached a predetermined value. The reaction period at 0.08 MPa was 10 min. Subsequently, the interior of the system was pressurized with nitrogen, and the polymer was collected from the filament mold and pelleted to provide approximately 13 kg of a polyamide resin. The resulting polyamide resin had a melting point of 189 ° C and a glass transition point of 84.5 ° C.

Comparative examples 4 and 5 The polyamide resins were synthesized in the same manner as in Example 15 except that the sebacic acid was replaced by SA14 and SA15 having the characteristics described in Table 3. The resulting polyamide resins both had a melting point of 189 ° C. and a glass transition point of 84.5 ° C.

The YI values, flexural moduli of elasticity and tensile strength retentions of the polyamide resins obtained above were evaluated in the same manner as in Examples 8-14. The results of the evaluation are described in Table 3.

Table 3 Examples 22 Example 22 A reaction vessel equipped with a stirrer, a partial condenser, a total condenser, a thermometer, a dropping funnel and a nitrogen inlet as well as a filament mold was charged with 12.135 g (60.00 mol) of sebacic acid (SA11) , and purged thoroughly with nitrogen and then heated to 170 ° C while the interior of the system is stirred under a small amount of nitrogen gas stream.

To this, 8.413.8 g (60.00 mol) of a BAC mixture composed of 1,3-bis (aminomethyl) cyclohexane (BAC, cis / trans molar ratio: 15/85) was added dropwise (ratio of the mixture 1, 3). -BAC / l, 4-BAC: 70/30) available from Mitsubishi Gas Chemical Company, Inc. with agitation and the interior of the system was continuously heated while the condensed water generated was removed from the system. After completion of the dropwise addition of the bis (aminomethyl) cyclohexane mixture, the melt polymerization reaction was continued for 40 min at an internal temperature of 240 ° C.

Subsequently, the interior of the system was pressurized with nitrogen, and the polymer was collected from the filament mold and pelletized to provide approximately 22 kg of a polymer resin. The resulting polymer resin had a melting point of 191 ° C and a glass transition point of 71 ° C. The DSC analysis showed no peak of crystallization on the low temperature, confirming that the polyamide is almost amorphous.

Example 23 A polyamide resin was synthesized in the same manner as in Example 22 except that a BAC mixture composed of 1,3-bis (aminomethyl) cyclohexane (BAC, cis / trans molar ratio: 70/30) and 1.4- bis (aminomethyl) cyclohexane (BAC, cis / trans molar ratio: 15/85) (ratio of the mixture 1, 3-BAC / l, -BAC: 30/70) available from Mitsubishi Gas Chemical Company, Inc., was used and the internal temperature after completing the addition by dripping was 270 ° C. The resulting polyamide resin had a melting point of 255 ° C and a glass transition point of 92 ° C.

The YI values, flexural moduli of elasticity and the tensile strength retentions of the polyamide resins obtained above were evaluated in the same manner as in Examples 8-14. The results of the evaluation are shown in Table 4.

Table 4 INDUSTRIAL APPLICATION The polyamide resins of the present invention possess an excellent color tone and elastic modulus as well as excellent gas barrier properties and low water absorption so that these can be widely used for various applications and can be suitable for use in a wide variety of moldings including various films, sheets, laminated films, tubes, hoses, tubing, various containers such as empty containers and bottles, various parts and the like, and consequently, they can find a wide industrial application.

Claims (9)

REIVI DICACIONES

1. A polyamide resin comprising a diamine structural unit and a structural unit of 5 dicarboxylic acid, wherein 70 mol% or more of the diamine structural unit is derived from xylylenediamine and / or bis (aminomethyl) cyclohexane and 50 mol% or more of the structural unit of dicarboxylic acid is derived from sebacic acid; and which has a sulfur atom concentration of 1 to 200 ppm per mass. 10

2. The polyamide resin according to claim 1, characterized in that it has a phosphorus atom concentration of 1 to 500 ppm per mass.

3. The polyamide resin according to claim 1 or 2, further characterized in that it has a sodium atom concentration of 1 to 500 μm per mass.

4. The polyamide resin according to claim 1, further characterized in that the xylylenediamine is m-xylylenediamine, p-xylylenediamine or one or mixture of them.

5. The polyamide resin according to claim 1, further characterized in that the bis (aminomethyl) cyclohexane is 1, -bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane or a mixture thereof.

6. The polyamide resin according to claim 1, further characterized in that the structural unit of dicarboxylic acid is derived from sebacic acid.

7. The polyamide resin according to claim 1, further characterized in that it has an average molecular weight number of 10,000 to 50,000.

8. The polyamide resin according to claim 1, further characterized in that the molar reaction ratio of the diamine component to the dicarboxylic acid component represented by the following equation (1) is 0.98 to 1.1; r = (1-cN-b (C-N)) / (1-cC + a (C-N)) (1) where a = i / 2, b = M2 / 2, c = 18.015, where i represents the molecular weight of the diamine component (g / mol), M2 represents the molecular weight of the dicarboxylic acid component (g / mol) , N represents the concentration of a terminal amino group (eq / g), and C represents the concentration of a terminal carboxyl group (eq / g).

9. A molded article formed by molding a polyamide resin according to any of claims 1-8.